Introduction: Occupational balance, a foundational concept in occupational therapy and science, plays a critical role in enhancing health and well-being. Recent studies have revealed its association with epidemiological factors. This study evaluated the validity and reliability of the Japanese version of the Occupational Balance Questionnaire 11 (OBQ11-J).

Methods: Adhering to the COnsensus-based Standards for the selection of health Measurement INstruments and Rasch Reporting Guidelines for Rehabilitation Research, analyses were conducted on the OBQ11-J using a cohort of 462 generally healthy individuals.

Results: The mean OBQ11-J score was 17.7 +/- 5.1, ranging from 2 to 33. Two items (Items 1 and 9) exhibited ceiling effects. The 4-point rating scale was validated. Although two items (Items 1 and 10) did not strictly conform to the Rasch model, the overall one-dimensionality and single-factor structures were supported. This confirms the structural validity of the OBQ11-J with its 11 items and 4 rating stages. Reliability, assessed through internal consistency, person separation reliability and test-retest reliability, further affirmed the instrument's robustness.

Conclusion: The OBQ11-J demonstrated validity and reliability in a sample of healthy Japanese individuals. Future investigations should establish normative values for the Japanese population and examine criterion-related validity, responsiveness and interpretability.